Corrugated flexible hose coupling system

ABSTRACT

A coupling system for corrugated, flexible metal hoses includes fitting and washer assemblies. The fitting assembly comprises inner and outer fittings, the inner fitting being received on the hose and having a bore adapted to receive the washer assembly. The washer assembly includes an O-ring, a backer washer and an expandable washer. The O-ring forms a seal connection with the flexible metal hose and the fitting assembly. The expandable washer provides a stop against which the backer ring is pushed by the O-ring. The expandable washer is also clamped between the fitting assembly and a corrugation of the flexible hose to resist withdrawal of the latter. Modified embodiment hose coupling systems are also disclosed and include inner and outer gaskets, compression gaskets, termination plates mounting the outer fitting and different combinations of retainer rings, backer rings and gasket rings. An application of the coupling systems includes a fuel source, a fuel line, a manifold, the coupling system, a corrugated flexible hose and a gas-fired appliance.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to hose couplings, and inparticular to a coupling system for a corrugated, flexible metal hose.

2. Description of the Related Art

Hoses, conduits, pipes and the like are commonly used to convey a widevariety of different fluids. Many such applications require flexiblemetal hose to accommodate relative movement between system componentsbeing connected. For example, fuel lines intended to convey gaseousfuels (e.g. natural gas or propane), are commonly constructed offlexible metal hose.

To accommodate relative movement in gaseous fuel systems, the fuel linesare often flexible. For example, flexible corrugated metal hose iscommonly used for connecting a wide variety of gas-fired appliances togas sources. Such corrugated metal hose has several advantages,including flexibility and an ability to extend and contract. Moreover,it is relatively inexpensive to manufacture and its use tends to reducethe need to precisely position a gas-fired appliance with respect to agaseous fuel source. Therefore, installation of gas-fired appliances canbe facilitated because exact placement is not necessary and approximatepositioning can be accommodated by a flexible gas line. Gas lines can bepermanently installed in a building and routed through the structurefrom a gas source to the general location of gas-fired equipment andappliances. Less-permanent gas lines are often used for making the finalconnections to the appliances themselves, and are commonly referred toas "whips". Gas line whips are commonly fabricated from lengths ofcorrugated, flexible metal hose. Both permanent gas lines and whip gaslines require secure end connections. Whip gas lines are commonly usedwith appliances which are subject to some degree of movement, such asgas-fired dryers, ovens and the like.

Design criteria common to such gas lines include providing relativelysecure, fluid-tight seals and providing sufficiently strong endconnections to avoid a separation or pull-out of the line from theappliance or other equipment. In the case of a gaseous fuel line, leakscan be very dangerous since many gas fuels are by nature both toxic andhighly flammable. Thus, to avoid accidental gas poisoning or explosion,structurally secure systems are very important.

In the case of rigid gas lines, sufficient material thickness is oftenpresent to provide threaded fittings, which tend to be relatively secureand leak-resistant. With corrugated flexible metal hose, however, thematerial is often relatively thin-walled and thus not sufficiently thickto accommodate threading.

To address the problem of providing secure fittings on flexible metalhose, various coupling systems have been devised. These include avariety of compression fittings, washers, O-rings and gaskets. However,heretofore there has not been available a coupling system for acorrugated flexible hose with the advantages and features of the presentinvention.

SUMMARY OF THE INVENTION

In the practice of the present invention, a coupling system is providedfor coupling a flexible metal hose with annular or spiral corrugationsto a device, such as a gas-fired appliance or a fuel source. The hosecoupling system includes a fitting assembly with inner and outerfittings adapted for threaded inter-connection on the end of theflexible hose. The inner fitting includes a bore which receives a washerassembly with an O-ring for forming a sealing connection, a backer ringand an expandable washer. The expandable washer is selectivelyreceivable on the corrugations of the flexible hose and functions toretain the fitting and washer assemblies securely in place and toprevent pull-out of the coupling while providing a positive connectionto the hose whereby the O-ring gasket can be compressed for an effectiveseal.

OBJECTS AND ADVANTAGES OF THE INVENTION

The principal objects and advantages of the present invention includeproviding a coupling system for flexible hoses; providing such acoupling system which is easily mounted on various corrugated flexiblemetal hoses; providing such a coupling system which provides arelatively secure connection; providing such a coupling system whicheffectively resists pull-out; providing such a coupling system whichfacilitates relatively quick installation; providing such a couplingsystem which facilitates the installation of gas-fired appliances;providing such a coupling system which at least partly utilizes commonlyavailable components; providing such a coupling system which isadaptable for providing coupling connections to various gas-firedappliances; providing such a coupling system which facilitates positionadjustments in gas-fired appliance installations; providing such acoupling system which provides positive engagement for an expandablewasher with corrugations of a flexible metal hose; providing such acoupling system which is economical to manufacture, simple to install,capable of a long operating life and particularly well-adapted for theproposed usage thereof.

Other objects and advantages of this invention will become apparent fromthe following description taken in conjunction with the accompanyingdrawings wherein are set forth, by way of illustration and example,certain embodiments of this invention.

The drawings constitute a part of this specification and includeexemplary embodiments of the present invention and illustrate variousobjects and features thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded, perspective view of a corrugated hose couplingsystem embodying the present invention.

FIG. 2 is an enlarged, longitudinal cross-section of the couplingsystem.

FIG. 3 is a transverse, cross-sectional view of the coupling systemtaken generally along line 3--3 in FIG. 2.

FIG. 4 is a plan view of a retaining washer of a corrugated hosecoupling system comprising a first modified embodiment of the presentinvention.

FIG. 5 is a side elevational view of the retaining washer of the firstmodified embodiment.

FIG. 6 is an exploded, perspective view of a corrugated hose couplingsystem comprising a second modified embodiment of the present invention.

FIG. 7 is an enlarged, longitudinal cross-section of the second modifiedembodiment corrugated hose coupling system.

FIG. 8 is an enlarged, longitudinal cross-section of the second modifiedembodiment corrugated hose coupling system.

FIG. 9 is an exploded, side elevational view of a corrugated hosecoupling system comprising a third modified embodiment of the presentinvention.

FIG. 10 is a side elevational view of the third modified embodiment hosecoupling system, shown assembled.

FIG. 11 is an enlarged, transverse, cross-sectional view of the thirdmodified embodiment corrugated hose coupling system, particularlyshowing a termination plate thereof and taken generally along line11--11 in FIG. 10.

FIG. 12 is an exploded, side elevational view of a corrugated hosecoupling system comprising a fourth modified embodiment of the presentinvention.

FIG. 13 is an enlarged, longitudinal, cross-sectional view of the fourthmodified embodiment corrugated hose coupling system.

FIG. 14 is an exploded, side elevational view of a corrugated hosecoupling system comprising a fifth modified embodiment of the presentinvention.

FIG. 15 is an enlarged, longitudinal, cross-sectional view of the fifthmodified embodiment corrugated hose coupling system.

FIG. 16 is a schematic diagram of an application of the corrugated hosecoupling system of the present invention.

DETAILED DESCRIPTION OF THE INVENTION I. Introduction and Environment

As required, detailed embodiments of the present invention are disclosedherein; however, it is to be understood that the disclosed embodimentsare merely exemplary of the invention, which may be embodied in variousforms. Therefore, specific structural and functional details disclosedherein are not to be interpreted as limiting, but merely as a basis forthe claims and as a representative basis for teaching one skilled in theart to variously employ the present invention in virtually anyappropriately detailed structure.

Referring to the drawings in more detail, the reference numeral 2generally designates a hose coupling system embodying the presentinvention and adapted for connecting a flexible hose 4 and generallycomprising a fitting assembly 6 and a washer assembly 8.

The flexible hose 4 includes corrugations 10 with alternating lands andgrooves 10a, 10b and can include an identifying (e.g., color-codedyellow for gas) covering 12. Without limitation on the generality ofhoses which can be coupled with the coupling system 2, the flexible hose4 can primarily comprise metal with the identifying covering 12comprising plastic.

The hose coupling system 2 can be utilized to connect the flexible hose4 to, for example, appliances, equipment, natural gas or propane supplysources, fuel tanks and other hoses. See, for example, FIG. 16.

II. Fitting Assembly 6

The fitting assembly 6 includes inner and outer fittings 6a, 6b. Theinner fitting 6a can comprise a slip nut with a generally hexagonal body14 having an inner end 16 with a receiver 18 slidably receiving theflexible hose 4 and an outer end 20. A female-threaded bore 22 is openat the outer end 20. The bore 22 terminates at a shoulder 24 surroundingthe receiver 18 in proximity to the inner end 16.

The outer fitting 6b includes a male-threaded inner end 26 threadablyengageable with the female-threaded bore 22 of the inner fitting 6a anda male-threaded outer end 28. A medial hexagonal nut 30 is positionedbetween the inner and outer ends 26, 28. A bore 32 extends between theinner and outer ends 26, 28 and comprises inner and outer bore sections32a, 32b with a bore shoulder 32c located therebetween. Although thefitting assembly 6 is shown and described with a particular combinationof male and female threaded components, other configurations of fittingscould be utilized with the hose coupling system 2 of the presentinvention. For example, the outer fitting 6b could have afemale-threaded outer end.

III. Washer Assembly 8

The washer assembly 8 includes: a rubber or elastomeric O-ring 34;backer ring 36 comprising plastic, metal, high-temperature ceramic orsome other suitable materials and an expandable washer 38. The O-ring 34has an outside diameter (OD) which can be sized to fit within the innerfitting bore 22 and an inside diameter (ID) generally corresponding tothe diameter of the hose 4 at a respective corrugation groove 10b. TheO-ring 34 is preferably sized to fit closely within a respective hosecorrugation groove 10b.

The plastic backer ring 36 also has an OD adapted to fit within thethreaded bore 22 and has an ID which is slightly greater than thediameter of the hose lands 10a whereby the backer ring 36 is adapted toslidably receive the hose 4.

The washer assembly 8 further includes an expandable washer 38comprising a generally annular body 38a forming a receiver 38b andhaving first and second faces 38c,d. The washer body 38a forms aperimeter 38e. A slot 38f extends between and is open at the washerreceiver 38b and the washer perimeter 38e. A notch 38g is formed in thewasher body 38a generally opposite the slot 38f and is open to thereceiver 38b thereof. The expandable washer 38 has an inside diameterdefined by the receiver 38b which is greater than a diameter of the hose4 at a groove 10b thereof and less than the hose diameter at a land 10athereof. The expandable washer 38 is thus retained in place on theflexible hose 4 by the corrugations 10.

IV. Operation

In operation, the hose coupling system 2 is assembled as shown in FIG. 2and functions to effect a relatively secure connection between theflexible hose 4 and the fitting assembly 6 whereby a relatively secureand fluid-tight seal is formed therebetween. More specifically, theexpandable washer 38 is engaged on one face 38c thereof with the innerfitting inner end 16 and with a respective corrugation land 10a. Aconnection is formed with the hose coupling system 2 by first insertingthe end of the flexible hose 4 through the inner fitting receiver 18whereby the inner fitting 6a is positioned on the flexible hose 4 withits threaded bore 22 open outwardly. Next the expandable washer 38 isinstalled by expanding its receiver 38b to receive the flexible hose 4.Expansion of the expandable washer 38 is facilitated by the cooperationof the slot 38f with the notch 38g located diametrically oppositetherefrom, which permits sufficient expansion to receive the flexiblehose 4. The expandable washer 38 can then snap or be bent into place ina respective groove 10b.

When properly positioned, the expandable washer 38 snaps into place atleast partly in a respective corrugation groove 10b, preferably at least2 grooves 10b back from an end 4a of the flexible hose 4. The backerring 36 can then be placed over the flexible hose 4 into engagement withthe expandable washer second face 38d. The O-ring 34 is stretched overthe flexible hose end 4a and snaps into place in, for example, the nextcorrugation groove 10b out from the groove 10b receiving the expandablewasher 38.

The inner fitting 6a is then brought into engagement with the expandablewasher 38 and threadably receives the inner, male-threaded end 26 of theouter fitting 6b, the inner end 26 of which engages the O-ring 34 andexpands same through a clamping action. The O-ring 34 is thus expandedinto sealing engagement with corrugation lands 10a on both sides of arespective corrugation groove 10b. The backer ring 36 tends to be drawnoutwardly and into engagement with the O-ring 34 by the action ofthreadably screwing the outer fitting 6b into the inner fitting 6a, thusfacilitating expansion of the O-ring 34 into its sealing engagement. Thethickness of the backer ring 36 is preferably sized to space theexpandable washer 38 and the O-ring 34 apart approximately the spacingof an adjacent pair of flexible hose grooves 10b.

The expandable washer 38 resists pulling out of the flexible hose 4 fromthe coupling system 2 by abutting a respective corrugation land 10a.With the expandable washer 38 captured within the inner fitting bore 22,it is prevented from expanding and thus securely retained within arespective corrugation groove 10b. The hose coupling system 2 thusoffers substantial resistance to being pulled apart, even if significantforce is exerted on the flexible hose 4.

V. First Modified Embodiment Hose Coupling System 102

A corrugated hose coupling system comprising a first modified embodimentof the present invention is shown in FIGS. 4 and 5 and is generallydesignated by the reference numeral 102. The coupling system 102includes a modified expandable washer 138 which includes a generallyannular body 138a with a concentric, generally circular receiver 138b, afirst face 138c, a second face 138d and a perimeter 138e. A slot 138f isformed in the body 138a and extends radially from the receiver 138b tothe perimeter 138e. The slot 138f is open at first and second slotmouths 138f.1, 138f.2 formed at the washer first and second faces 138c,138d respectively. The slot mouths 138f.1, 138f.2 are staggered and arepositioned in circumferentially-spaced relation on the body 138a wherebyangled first and second body ends 138h.1, 138h.2 overly each other withslot 138f extending at a slant forming an acute angle with respect to alongitudinal axis 140 of the coupling system 102.

A notch 138g is formed in the body 138a and extends partway therethroughfrom the receiver 138d to facilitate spreading the expandable washer138. The angled, slanted orientation of the slot 138f facilitatesmaintaining a fluid-tight seal with the O-ring 34. Thus, slightexpansions and retractions of the washer 138 will not interfere with itscontinuity since the slot 138f accommodates slight movements of the bodyends 138h.1, 138h.2 with respect to each other. The continuity of thewasher 138 facilitates engagement by the O-ring 134.

VI. Second Modified Embodiment Hose Coupling System 202

A hose coupling system 202 comprising a second modified embodiment ofthe present invention is shown in FIGS. 6, 7 and 8. The hose couplingsystem 202 is adapted for mounting on a flexible hose 204 with an end204a and spiral-wound corrugations 210 with alternating lands andgrooves 210a,b. The hose connection system 204 includes a gasket 234which threadably mounts on the flexible hose end 204a. The gasket 234includes first and second ends 234a,b, a female-threaded bore 234cextending therebetween and open threat and a generally frusto-conicalouter surface 234d with a configuration generally corresponding to theouter fitting bore inner section 232a. The gasket outer surface 234dcould be configured to accommodate various fittings, and could be, forexample, generally cylindrical. The gasket 234 can include alongitudinal slit 234e which facilitates snapping it on the flexiblehose end 204a. Alternatively, the gasket 234 can be threaded onto theflexible hose end 204a.

In operation, the gasket 234 functions to form a fluid-tight seal withthe outer fitting assembly 6b and the flexible metal hose 4. Theshoulder 32c of the outer fitting 6b engages the gasket first end 234aand expands same against the outer fitting inner end 26. Thefemale-threaded gasket bore 234c cooperates with the flexible hosecorrugations 210 to provide substantially continuous sealing in the hoseconnection system 202. Moreover, threaded engagement between theflexible hose end 204a and the gasket 234 provides substantialresistance to tensile forces, which might otherwise tend to pull thehose connection system 202 off of the flexible hose 204.

An optional backer ring 236 can be provided over the hose 204 andabutting the inner fitting shoulder 24 and the gasket first end 234a.The presence or absence of the backer ring 236, and its size, can beused to control the position of the inner fitting 6a with respect to theouter fitting 6b.

VII. Third Modified Embodiment Hose Coupling System 302

A hose coupling system comprising a third modified embodiment of thepresent invention is shown in FIGS. 9-11 and is generally designated bythe reference numeral 302. The hose coupling system 302 includes aretainer ring 304 which can comprise, for example, an expandable washersuch as the previously-described expandable washer 38, which can befabricated from a suitable material such as, for example, stainlesssteel. The stainless steel retainer ring 304 engages the flexible hose 4and is retained within a corrugation groove 10b by an inner fitting 6a.

A slider ring 306 is slidably positioned over the corrugated flexiblehose 4 and engages the retainer 304. A slider ring 306 can comprise, forexample, plastic, metal, high-temperature ceramic or some other suitablematerial A silicon gasket 308 with the general configuration of anO-ring is located outboard the slider ring 306 and engages the inner end26 of the male-threaded outer fitting 6b. Tightening the inner fitting(nut) 6a on the outer fitting 6b compresses the silicon gasket O-ring308 against the outer fitting inner end 26 to form a sealing connectiontherebetween.

The third modified hose coupling system 302 includes a termination plate310 which includes a threaded, female central receiver 312 and aplurality of corner receivers 314. The termination plate 310 is adaptedfor mounting on a wall by means of mechanical fasteners, such as screwsor the like (not shown), extending through the corner receivers 314 andinto the wall structure (not shown). The outer fitting outer end 28 isthreadably received in the termination plate central receiver 312 andextends into the wall cavity for connection to a component of a gas fuelsystem, such as a fuel line or the like.

VIII. Fourth Modified Embodiment Hose Coupling System 402

A corrugated flexible hose coupling system comprising a fourth modifiedembodiment of the present invention is shown in FIGS. 12-13 and isgenerally designated by the reference numeral 402.

The fourth modified embodiment hose coupling system 402 includes aretainer ring or expandable washer 404 which can be similar, forexample, to the expandable washer 38 described above which receives thecorrugated flexible hose 4 and is retained on a groove 10b thereof bythe inner fitting 6a. A high temperature sealing ring 406 is receivedwithin the outer fitting bore inner section 32a and engages the outerfitting shoulder 32c. As shown in FIG. 13, the corrugated flexible hose4 can be compressed between its end 4a, which engages the sealing ring406, and the retainer ring 404. Compression of the flexible hosecorrugations 10 can facilitate a tight seal of the sealing ring 406. Theamount of compression of the flexible hose corrugations 410 can becontrolled by the extent to which the outer fitting inner end 26 isthreadably received in the inner fitting threaded bore 22. Thecorrugated flexible hose coupling system 402 provides significantperformance advantages since the corrugated flexible hose 4 extends intothe outer fitting bore inner section 32a and since the inner fitting 6acan be used to compress the corrugated flexible hose 4 for tighteningthe sealing engagement on the sealing ring 406.

IX. Fifth Modified Embodiment Flexible Hose Coupling System 502

A hose coupling system comprising a fifth modified embodiment of thepresent invention is shown in FIGS. 14-15 and is generally designated bythe reference numeral 502. The hose coupling system 502 is designed tocouple a corrugated, flexible hose 4 to a fitting assembly 6 comprisingan inner fitting 6a and an outer fitting 6b.

A retainer ring or expandable washer 504 is received on the flexiblecorrugated hose 4 and retained in a groove 10b thereof. The retainerring or expandable washer 504 can comprise, for example, an expandablewasher or C-clip such as that described above and designated by thereference numeral 38.

A backer ring 508 comprising stainless steel or some other suitablematerial slidably receives the flexible hose 4 and is positionedoutboard the retainer ring 504 in engagement with same. A silicon gasketO-ring 510 is positioned in the hose groove 10b next outboard from thehose groove 10b receiving the retainer ring 504. A compression gasket orhigh-temperature sealing ring 512 is positioned in the throat or boreinner section 32a of the outer fitting 6b. The compression gasket 512can comprise a suitable material such as plastic, metal,high-temperature ceramic, etc., which material can be chosen to performwithin the temperature and pressure ranges of particular applications ofthe fifth modified hose coupling system 502.

In operation, the fifth modified hose coupling system 502 can beassembled by inserting the compression gasket 512 against the outerfitting bore shoulder 32c within the outer fitting bore throat 32a. Theflexible hose end 4a, with the retainer ring 504, the backer ring 508and the O-ring 510 mounted thereon (FIG. 14) is then inserted into theouter fitting bore throat 32a until the flexible hose end 4a engages thecompression gasket 512 and the O-ring 510 engages the outer fittinginner end 26. The retainer ring 504, the backer ring 508, and the O-ring510 collectively form inner gasket means 506a and form a seal betweenthe flexible hose 4 and the outer fitting inner end 26. The engagementof the compression gasket 12 with the shoulder 32c and the hose end 4aform outer gasket means 506b. Thus, the hose coupling system 402 formsindependent seals comprising inner and outer gasket means 506a,b. Thetightness of the inner and outer gasket means 506a,b can be adjusted bythreadably adjusting the inner fitting 6a on the outer fitting 6b, thuseffecting a clamping action with respect to the inner and outer gasketmeans 6a, 6b. Moreover, the hose corrugations 10 can compress somewhatas the hose end 4a engages the compression gasket 512 for biasing sametightly into engagement with the shoulder 32c.

The threaded interconnection of the inner and outer fittings 6a, 6bfacilitate servicing the hose coupling systems of the present invention,whereby their respective gaskets and other components can be replaced.Moreover, pipe joint compounds, caulks and other viscous or semi-viscousmaterials could be used in connection with the hose coupling systems ofthe present invention to enhance the sealing, coupling andcorrosion-resistant characteristics thereof.

X. Hose Coupling System Application 602

Without limitation on the generality of useful applications of the hosecoupling systems of the present invention, an exemplary applicationcomprising an environment is shown in FIG. 16 and is generallydesignated by the reference numeral 602. The application 602 includes afuel source 604, such as a tank, supply line or other source of fuelsuch as propane, natural gas, etc. The fuel source 4 is connected by afuel line 606 to a manifold 608 which can mount a plurality (e.g., twoare shown) of hose coupling systems 210 embodying the present invention.The hose coupling systems 610 fluidically connect the manifold 608 tocorrugated flexible hose sections 612 at their first ends 614a. Secondends 614b of the flexible hose section 612 are connected to appliances616 by additional hose coupling systems 610. Without limitation ofgenerality of useful applications of the hose coupling systems 610, theycan be used for connecting virtually any appliance or device whichconsumes gaseous fuel, such as, for example, furnaces, hot waterheaters, ovens, stoves, heaters, etc. Moreover, the system can beexpanded to include various numbers of appliances 216, etc.

It is to be understood that while certain forms of the present inventionhave been illustrated and described herein, it is not to be limited tothe specific forms or arrangement of parts described and shown.

What is claimed and desired to be secured by Letters Patent is asfollows:
 1. A coupling system for a flexible hose with corrugations andan end, which comprises:(a) a fitting assembly including:(1) an innerfitting with inner and outer ends, a receiver receiving the flexiblehose in its inner end, a shoulder projecting radially inwardly into saidinner fitting receiver and a female-threaded bore open at its outer endand communicating with said receiver; and (2) an outer fitting with amale-threaded inner end threadably receivable in said inner fittingfemale-threaded bore, an outer end, a bore extending between said outerfitting ends and having a bore inner section adjacent said outer fittinginner end and a bore outer section adjacent said outer fitting outerend; (b) an expandable washer having an expanded, first position passingthe hose therethrough and a constricted, second position clamping saidhose between corrugations thereof, said washer being positioned withinsaid fitting assembly in engagement with said inner fitting shoulder inits constricted second position; (c) a backer ring slidably receivingthe hose and positioned within the fitting assembly in engagement withthe expandable washer; and (d) a sealing ring comprising an O-ringengaging the backer ring, the hose and the outer fitting inner end, saidO-ring including sealing means for forming a seal between the hose andthe fitting assembly, said 0-ring being compressed between said outerfitting inner end and said backer ring and said backer ring spacing saidO-ring in a groove in the corrugated hose.
 2. The coupling systemaccording to claim 1 wherein:(a) said expandable washer having agenerally annular body, a receiver, first and second faces, a perimeterand a slot extending from said receiver to said perimeter.
 3. Thecoupling system according to claim 2 wherein said expandable washerincludes a notch open to said receiver and positioned in spaced relationfrom said slot.
 4. The coupling system according to claim 2, whichincludes:(a) said expandable washer slot extending at a skewed anglebetween said washer first and second faces.
 5. The coupling systemaccording to claim 1, which includes:(a) said outer fitting having amale-threaded outer end; and (b) a termination plate including afemale-threaded central bore threadably receiving said outer fittingouter end.
 6. The coupling system according to claim 1 wherein saidflexible hose corrugations are annular.